Method of producing photographic pictures in colors



Patented Nov. 12, 1935 METHOD OF PRODUCING PHOTOGRAPHIC PICTURES IN COLORS Bla Gaspar, Brussels, Belgium No Drawing. Application October 30, 1931, Serial No. 572,232. In Germany November 7, 1930 28 Claims.

This invention relates to a method of producing photographic pictures in colors.

The present invention avoids the disadvanages of all former known methods it being pos- 5 sible according to the invention to obtain in direct fashion from diffusely'colored positive or negative silver-deposit images, respectively positive or negative color images. There is awide range of selection as regards the dyes employed, as it is possible to use dyes of different classes. It is possible to convert a silver image into a color picture in a shortness of time heretofore unknown.

The methodof producing reversed dyestuif images according to the present invention is characterized in that photographic images, diffusely colored with non-leuco base forming dyestufis and consisting of a metal deposit image, have the dyestufi permanently decolorized, bleached or destroyed at the points of the metal deposit by means of a fluid agent which itself is incapable, during the normal time of treatment, of destroying the dye by oxidation or reduction but de-colorizes, bleaches or destroys the dye by the formation of reducing reaction products or reducing complex compounds of the metal. These reducing agents are formed and act while the finely distributed metal is attacked by the treating agent.

These reagents will be referred to as nondestructive means in the claims, or non-destructive compounds, asthe same do not attack the dyestuff at the points free of 'metal deposit for such periods'of treatment as are concerned in actual practice.

An example of such a non-destructive bath, is given below:

/ Grammes Thiourea 10 Citric acid 5 Water 200 In the case of these baths there occurs a destruction of the dyes simultaneously with an oxidation of the metallic image at the points where silver is present, 1. e. the metallic silver is' converted into a silver compoumhwhch may be dssolved.

Reagents whch are destructive" within the meaning of the present invention are, for example, the following substances which act detrimentally on the dyestuifs or on the photographic layer: powerful oxidizing and etching agents such aspotassium permanganate, bromic acid and hydrogen peroxide; powerful reducing agents such as sodium hydrosulphite and stannous chloride (SnCla)'; powerful concentrated acids such as concentrated sulphuric acid and con centrated solutions of potassium or sodium hydroxide. This is not intended to be a'complete 5 list of destructive. reagents, but serves to indicate the types of reagents which are not used in the present invention.

- It has been found that a large number of compounds act in a manner to reverse a silver 10 depositimage, i. e. to destroy the dye in a difiusely colored silver image :at the points of the silver deposit, there being formed at first silver salts and reducing agents, which act locally in destructive fashion on the dye, or the metallic 15 silver image passing into solution with formation of a complex compound, this also acting in color-destructive manner. Practically all sulphur compounds which possess the above-mentioned properties are suitable for this purpose, 20

organic or inorganic, also nitrous organic compounds of the urea group for example allylthiourea, diphenyl thiourea, or similar compounds, or isomers of sulphuric ureas, cyanides, thio-cyanates, etc., for example sodium sulphide, 25 calcium polysulphide, cystein salts, guanidine, amino guanidlnes, thiodiglycolic acid, thio-semicarbazide, semi-carbazide, etc. It is shown that these substances are efiective in neutral, alkaline or acid solution. The effectiveness of th "se com- 30 pounds, however, greatly varies, and is in part of a very slow kind, so that the same are not all equally suitable for practical purposes. According to the invention, however, the effect may be greatly accelerated if reducing substances are 35 added with or without acid, which substances alone do not destroy the dye or are only effective in very slow fashion, or also by adding a plurality of little eilective agents. Reducing substances of this nature are phenols, amino phenols 40 and their substitutional productsaldchyde, sugar, etc., or possibly also acids. The addition of these substances also acts in accelerating fashion in the case of the means referred to above.

To the above baths it is also possible to add 45 a hardening means, such as alum.

Obviously it is also possible under certain cir I cumstances to replace the metallic silver-deposit image by a deposit of equal efiect of another metal, for example mercury. 50

The majority ofthe substantive and acid azodyes, and some basic dyes, vat dyes, alizarine dyes, etc., may be used for this purpose. By way of example there may be mentioned Heliotrope BB (321), Chlor-Amine light red 'IBL "tsandoz.

Basel, Switzerland), Diamine rose G (119), BBF (Casella), Diamlne pure blue FF (424), Naphtamine light blue 43 (Kalle & Co., Biebrlch), etc. All of these dyestuffs can be permanently destroyed by reducing means and they lose their dyestuii' character by this reduction process Their chemical constitution excludes the formation, by reduction, of a leuco-base. Therefore the colorless parts of the image, produced by the present invention, remain in this condition for a substantially unlimited period of time. Silver images colored throughout the layer are treatedin a color-destructive bath set forth below. The colors are here identified by numbers where known from the Schultz-Farbstofl-tabellen, edit. 5, 1920.

As example of color-destructive baths there may be mentioned the following:

Comrormns or THE UREA (TRIO-UREA AND rmrnounns) onours 1 Thiocarbamide.-A halogen silver layer is colored with azo-dyestufis, for example, Helitrope BB, Chloramine light red 7, Dlamine fast pink G, BBF (Casella) Diamine pure blue FF, Naphthamine light blue 4B, this emulsion being poured in the known fashion on to a. suitable backing. After developing and fixing, merely the silver im-- age is visible. The image is then treated with a solution of 5 grammes of thiocarbamide, 2 grammes of citric acid and 100 grammes of water. In this bath the silver is dissolved out simultaneously with the destruction of the dyestufi, v and should any traces of" silver deposit still remain in the picture, these are removed in a reducer.

2. Semi-carbazide.-A layer colored with Diamine fast pink G is treated with a solution comprising Grammes Water 100 Semi-carba g 5 Sulphuric acid 1 Grammes Water I 100 Thio semi-caibazide 5 Sulphuric. acid 1 The-rollowing treatment is then as in the preceding' examples.

4. Guandine.- -A layer colored with Heliotrope BB treated therewith.

5. Amido Guanidiney-A layer colored. with Diamine fast pink G treated therewith. The

following treatment is then as above.

In rnorssmo sunrrrun oourounns 1. Sodium sulphides-A layer colored with 131-: amine pure blue FF is treated with a solution Grammes Water 100 sodium sulphide; 5

and an addition of monomethyl paramido phenol sulphata, The following treatment is then as above.

' the deeper shadows.

INDIFFEEENT ORGANIC SULPHUR COMPOUNDS 1'. Thiodiglycolic acid.-A layer colored with Diamine fast pink G is treated with a solution comprising Grammes Water 100 Thiodiglycolic acid and grape sugar 5 'This example is also one of the uses of indifferent acids. 10 Naturally a short washing is required in water after the toning process. The baths may also be employed immediately following the development.

The rate of the color destruction depends in 15 the case of numerous dyes on the amount of free acids which may be present.

This method of simple conversion of the silver image into a color image may be employed with particular advantage in the case of.color phog0 tography and kinematography. variously colored part-layers selectively sensitive to diiferent spectral regions are poured one on top of the other, or diflerently colored and sensitized emulsions mixed together by a re-emulsifying process 5 (as described by Schinzel in the Chemiker Zeitung" 1908, page 665 Kothen, Anhalt, Germany) are simultaneously exposed and developed. The images, consisting of intimately connected part-images, are converted into the corresponda0 ing negative or positive multi-color image in one of the baths referred to in the above examples. Suitable dyes are, for example, Diamine pure blue FF (424) Mordant yellow GG (177), Diamine rose BBF (Casella) This method also provides the possibility of simple, cheap and rapid reversal of negatives and kinematograph films. In addition, this reversing process. also permits of the use of klnematograph films prior to the reversal as negatives.

In the case of substantive and acid dyes it is usually unnecessary to fix these in the gelatine. It is desirable, however, if a plurality of different colored layers are disposed one above the other toflx these in the known manner by mordant for- 45 mation or deposition. The sharpness of kinematograph films thus toned is also improved. For many purposes it is desirable toemploy dyes which bleach out with dlflerent speeds, for example if the layers in the case of multi-color photography are poured one upon the other and the destructive bath is more effective on the surface than in the depth of the part-layers a more slowly bleaching dye will therefore be employed. For the production of double tones very eflective colors may also be obtained if dyes of varying bleaching rapidity v are employed, for example azo Fuchsine B. (71) r and Dlamine pure blue FF (424). The first of these dyes bleaches very rapidly in a bath asde-; scribed in Example 1 under compounds of the urea groups, so that a blue color only remains in The effectiveness of these baths may be enhanced by the addition of catalytically acting salts, for example Va, U, Mo, Fe, etc. This method may also be used with advantage in the hand-coloring or stencil-coloring of kinematograph films, advertisement diapositives, photographs, etc. Thus, for example, in the case of a landscape illustration the sky may be dyed an intensive blue and the ground an intensive green. The dyes are then positively de-colored at the points of the silver image and converted into a reversed image. The concentration may be determined right at the commencement, and

taining inorganic deposit to oxidize stuff images in a photographic material, difiuse- 1y colored with a non-leuco base forming dyestufl which is permanently destroyable by reducing means and contains a finely divided metal deposit image, whichmonsists in treating said image with a fluid agent comprising a sulfur consalt solution which is non-destructive with respect to the dyestufi, but reacts with the said metal deposit to'oxidize it and substantially simultaneous'y to form a reducing substance which destroys said permanently destroyable dyestufi at the point of said metallic deposit.

9. A method of producing photographic dyestuif images in a photographic material, diffusely colored with a non-leuco base forming dyestuil which is permanently destroyable by reduc ing means and contains a ilnely divided silver deposit image, which consists in treating the said image with a fluidagent comprising weakly reducing compounds in addition to a'salt solution which is non-destructive with respect to the dyestufl, but reactswith the said silver deposit to oxidize it and substantially simultaneously to form a reducing substance which destroys said permanently destroyable dye-stuflat the point of said silver deposit.-

10. A method of producing photographic dyestufl images in a photographic material, difluse- -leuco base forming dyestuff which is permanently destroyable by reducing means and contains a finely divided metal deposit image, which consists in treating the said image with a fluid agent comprising an organic compound which is non-destructive with respect to the dyestuflf, but reacts with the said metal deposit to oxidize it and substantially simulta neously to form a reducing substance which destroys said permanently destroyable dyestufl at the point of said metallic deposit.

11. A method of producing photographic dyestufi images in a photographic material, diffusely colored with a no -leuco base forming dyestuii which is permanently destroyable by reducing means and deposit image, which consists in treating the said image with a fluid agent comprising an organic compound which is non-destructive with respect to the dycstuff, deposit to oxidize it and substantially simultaneously to form a reducing substance which destroys said permanently destroyable dyestufi at the point of said silver deposit. 1

12. A method of producing photographic dyestufi images in a photographic material, diffusely colored with a non-leuco base forming dyestuff which is permanently destroyable by reducing means and contains a finely dividedsilver deposit image, which consists in treating the said image with a fluid agent comprising weakcompounds in addition to an organic compound which is non-destructive with respect to the dyestufi, but reacts with the said silver it and substantially simultaneously to form a reducing substance whichdestroys said permanently destroyable dyestuff at the point of said silver deposit.

13. A method of producing photographic dyestufl images in a photographic material, ditiuseiy colored with a non-leuco base forming dyestufl which is permanently destroyable by reducing means and contains a finely divided silver deposit image, which consists in treating: the said image with a fluid agent comprising a nitrogeneous organic compound which is non-dely colored with a no contains a flnely divided silverbut reacts with the said silverv structive with respect to the dyestufl, but reacts with the said silver deposit to oxidize it and substantially simultaneously to form a reducing substance which destroys said permanently destroyable dyestui! at the point of said silver deposit.

14. A method of producing photographic dye- U stufl images in a photographic material, diflusely colored with a non-leuco base forming dyestufl which is permanently destroyable by reducing means and contains a finely divided silver deposit image,-which consists in treating the said image with a fluid agent comprising a nitrogeneous organic sulphur compound which is non-destructive with respect, to the dyestufi, but reacts with the said silver deposit to oxidize it and substantially simultaneously to form a reducing substance which destroys said permanently destroyable dyestufl at the point of said silver deposit.

15. A method of producing photographic dyestufl images in a photographic material, difiusely colored with a non-leuco base forming dyestufl which is permanently destroyable by reducing means and contains a finely divided silver deposit image, which consists in treating the said image with a fluid agent from a group consisting of urea, thiourea, guanidine, amino-guanidine, semi-carbazide, thiosemi-carbazide, thio-diglycolic acid, cyanide and thiocyanate. p

16. A method of producing photographic dyestuff images in a photographic material, diflusely colored with a non-leuco. base forming dyestufl which is permanently destroyable by reducing means and contains a. finely divided silver deposit image, which consists in treating the said image with a fluid agent comprising an acid in addition to a substance selected from a group consisting of urea, thiourea, guanidine, amino-guanidine,

semi-carb'azide, thioi-semi-carbazide, thio-diglycolic acid, cyanide and thiocyanate.

stufl images in a photographic material, diflusely colored with a non-leuco base forming azo dyestufl which is permanently destroyable by reducing meansand contains a finely divided metal deposit image, which consists in treating the said image with a fluid agent which is non-destructive with respect to the dyestuif, but reacts with the said metal deposit to oxidize it and substantially simultaneously to form a reducing substance which destroys said permanently destroyable dyestufl at the point of said metallic deposit.

19. A method of producing photographic dyestuff images in a photographic material, diffusely colored with a non-leuco base forming acid azo dyestufl which is permanently destroyable by reducing means and contains a finely divided metal deposit image, which consists in treatingthe said image with a fluid agent which is'non-des'tructive with respect to the dyestuff, but reacts with the said metal deposit to oxidize it andsubstantially simultaneously to comprising a substance'selected 25 form a reducing substance 75 2,020,775 which destroys said permanently. destroyable 'dyestuii at the point of said metallic deposit.

20, A method of producing photographic dyestuif images in a photographic material, difiusely stufi images in a photographic material, which consists in diffusely incorporating a permanently. reducible non-leuco' base forming azo dyestufl .in a light-sensitive photographic silver salt emulsion, applying the colored light-sensitive emulsion to a support, producing in the emulsion a silver deposit image in the'usual manner and then treating said image with a-fluid agent comprising a substance selected from a group consisting of urea, thiourea, guanidin, amino-guanidine, semicarbazide, thio-semi-carbazide, thio-diglycolic acid, cyanide and thio-cyanate.

22. A method of producing photographic dye;- stuff images ina photographic material, which consists in diifusely incorporating a permanently reducible ncn-leuco base torming. acid azo dye-, stuff in a light-sensitive photographic silver salt emulsicn,"applying the colored light-sensitive emulsion to a support, producing in the emulsion a silver deposit image in'the usual manner and then treating the'said image with a fluid agent comprising asubstance selected from a group consisting of urea, thiourea, guanidine, aminoguanidine, semi-carbazide, thio-semi-carbazide, thio-diglycolic acid, cyanide and thio-cyanate.

23. A method. of producing photographic dyestuff images in a photographic material, which consists in difiusely incorporating permanently reducible no-n-leuco base forming substantive acid azo dyestuffs in a light-sensitive photographic silver. salt emulsion, applying the colored light-sensitive emulsion 'to' a support, producing a silver deposit image in the usual manner in the emulsion and] then treating the said image with a fluid agent comprising a substance. selected from a group consisting of urea, thiourea, guanidine, amino-guanidine, semi-carbazide,,

thio-semi-carbazide, thio-dlglycolic acid, cyanide and thio-cyanate.

2 4. A method of producing photographic dyestufl images in a photographic material, which consistsin diitusely incorporating a permanently reducible non-leuco base forming acid azo dyestufi' in a light-sensitive photographic 'silversalt emulsion, applying the colored light-sensitive emulsion to asupport, producing a silver deposit image in the usual manner in'the emulsion and then treating the said image with a fluid agent containing wea reducing compounds in addition to a subs ce selected from a group consisting of urea, thio u'emguanidine, amino-guanidine, Qmi-carbalide, .thiogemi-carbazide, thiodlglycolle acid, cyanide and thio-cyanate.

25. A method of producing photographic dye-- stufi images in a photographic material, which consists in diffusely incorporating a permanently reducible non-leuco base forming acid azo dyestufi in a light-sensitive photographic silver salt emulsion, applying the colored light-sensitive emulsion to a support, producing a silver deposit image in the usual manner in the emulsion andthen treating said image with a fiuid agent containing'an acid and a weakly reducing compound in addition to a substance selected from a group consisting of urea, thiourea, guanidine, aminoguanidine, semi-carbazide, thio-semi-carbazide,

thio-diglycolic acid, cyanide and thio cyanate.

26. A method of producing photographic dyestufi images in a photographic material, which non-leuco baseforming azo dyestufls ina plurality of light-sensitive emulsions, applying these emulsions in a screenlike manner to a support, producing silver deposit images in each of the particles of saidemulsion and then treating the said images with a fluid agent which is non-destructive withrespect to the dyestuil, but reacts with said silver deposit to oxidize it and substantially simultaneously to form a reducing substance which destroys said permanently reducible dyestuffs at" the point of said silver-deposit. 2'7. A method of producing photographic dyestuil images in a photographic material, which consists in incorporating permanently reducible non-leuco base forming azo dyestuflfs of different "bleaching rapidity into different photographic photographic silver salt consists in incorporating permanently reducible support, producing silver deposit images in each {,0

- of said layers of emulsion and then treating said .silver deposit images witha fluid agent which is non-destructive with respect to the dyestuffs, but reacts with the silver deposit to oxidize it and substantially simultaneously to form a reducing 45 substance which destroys said permanently; re-

ducibledye-stuifs at the point of said silverdeposit. r

28. A method 01' producing photographic dyestufi images in a photographic material, which consists in incorporating permanently reducible deposits of non-leuco base forming acid azo dye'- stufis oi difierent bleaching rapidity into diil'erent photographic silverhalide emulsions, applying the emulsion containing the dyestufl oi'tne 5s highest bleaching rapidity to asupport and applying the emulsion containing the -dyestufl of the lowest bleaching rapidityover said first emul- ;sion on the same, support, producing silver deposit lmages in'each of said layers of emulsion and then treating said silver deposit images with a iluid agent which is non-destructive with respect to the dyestuffs, but reacts with the'sllver deposit to oxidize it and substantially simultaneously tofform a reducing'substance which destroys said permanently reducible dyestufll at the point of said silver deposit. 

